2018年湘潭大学程序设计竞赛 F

把点抽出来 跑个最短路就好啦。

#include<bits/stdc++.h>
#define LL long long
#define pii pair<int,int>
#define mk make_pair
#define fi first
#define se second
using namespace std;

const int N=300+7;
const int M=1e5+7;
const int inf=0x3f3f3f3f;
const LL INF=0x3f3f3f3f3f3f3f3f;
const int mod=1e9+7;

int n, m, q, idx, S, T, d[N * N], hs[N][N], dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1};
char s[N][N];

vector<pii> edge[N * N];


int Dj(int S, int T) {
    priority_queue<pii, vector<pii>, greater<pii> > que;
    d[S] = 0; que.push(mk(0, S));
    while(!que.empty()) {
        pii u = que.top();
        que.pop();
        if(u.fi < d[u.se]) continue;
        if(u.se == T) {
            return u.fi;
        }
        for(pii v : edge[u.se]) {
            if(d[u.se] + v.fi < d[v.se]) {
                d[v.se] = d[u.se] + v.fi;
                que.push(mk(d[v.se], v.se));
            }
        }
    }
    return -1;
}
void init() {
    idx = 0;
    for(int i = 0; i <= n * n + 10; i++)
        edge[i].clear(), d[i] = inf;
}

bool check(int x, int y) {
    if(x > n || x < 1) return false;
    if(y > m || y < 1) return false;
    if(s[x][y] == '#') return false;
    return true;
}
int main() {
    while(scanf("%d%d%d", &n, &m, &q) != EOF) {
        init();
        for(int i = 1; i <= n; i++)
            scanf("%s", s[i] + 1);
        for(int i = 1; i <= n; i++) {
            for(int j = 1; j <= m; j++) {
                hs[i][j] = ++idx;
                if(s[i][j] == 'S') S = idx;
                if(s[i][j] == 'T') T = idx;
            }
        }

        for(int i = 1; i <= n; i++) {
            for(int j = 1; j <= m; j++) {
                if(s[i][j] == '#') continue;
                for(int k = 0; k < 4; k++) {
                    int nx_x = i + dx[k];
                    int nx_y = j + dy[k];
                    if(check(nx_x, nx_y)) {
                        edge[hs[i][j]].push_back(mk(1, hs[nx_x][nx_y]));
                    }
                }
            }
        }

        for(int i = 1; i <= q; i++) {
            int a, b, c, d;
            scanf("%d%d%d%d", &a, &b, &c, &d);
            a++, b++, c++, d++;
            if(s[a][b] == '#' || s[c][d] == '#') continue;
            edge[hs[a][b]].push_back(mk(3, hs[c][d]));
        }

        int ans = Dj(S, T);
        printf("%d
", ans);
    }
    return 0;
}
/*
*/